code: def get_data(self):
      self._string.write("]")
      return self._string.getvalue()
  
file_path: FATE/python/fate/arch/federation/message_queue/_datastream.py
imports: import io
  import json
  import sys
label_desc: Use image node_id 3 for calling the Datastream obj's underlying member method code with example usage: obj.get_data() and returns: self